Dye for heat-sensitive transfer record, ink composition for heat-sensitive transfer record, and transfer sheet

ABSTRACT

A dyestuff for heat-sensitive transfer record is here disclosed which can be represented by the formula (1) ##STR1## wherein R 1  is a hydrogen atom, alkyl group having 1 to 8 carbon atoms or cycloalkyl group; R 2  is a hydrogen atom, halogen atom, alkoxy group which may be substituted, alkylthio group which may be substituted or arylthio group which may be substituted; R 3  is a branched alkyl group having 3 to 5 carbon atoms, O-substituted oxycarbonyl group, N-substituted aminocarbonyl group in which an N-substituted group may form a ring, or a substituted or unsubstituted heterocyclic ring having two or more atoms of one or more kinds selected from the group consisting of a nitrogen atom, oxygen atom and sulfur atom; and when R 1  is a hydrogen atom, R 3  is a branched alkyl group having 3 to 5 carbon atoms, or a substituted or unsubstituted heterocyclic ring having two or more atoms of one or more kinds selected from the group consisting of a nitrogen atom, oxygen atom and sulfur atom; 
     and there are also disclosed an ink for heat-sensitive transfer record and a transfer sheet in which the above-mentioned dyestuff is used.

BACKGROUND OF THE INVENTION

(i) Field of the invention

The present invention relates to a dyestuff for heat-sensitive transfer record (hereinafter abbreviated to "sublimable dyestuff"), an ink composition for heat-sensitive transfer record and a transfer sheet which can be used in color hard copies and the like utilizing a sublimation heat transfer record system.

(ii) Description Prior Art

A heat transfer record system using a sublimable dyestuff is one of the heat transfer print systems which comprise forming a transfer sheet by coating a thin condenser paper or PET film having a thickness of several microns with an ink of a sublimable dyestuff, and then selectively heating the transfer sheet by means of a heat-sensitive head to transfer the dyestuff to a record paper which is a material to be recorded. Nowadays, the heat transfer record system has been used as a means for the image record (hard copy) of much image information.

The sublimable dyestuffs which are used in the present invention are required to have abundant colors and strong adhesive force, and to be excellent in color mixing properties and stability. In the above-mentioned record system, the amount of the dyestuff to be sublimated depends upon heat energy, and so the density of the transferred dyestuff can be analogically controlled. This is a major feature which other printing systems cannot possess.

As yellow sublimable dyestuffs, there are quinophthalone compounds having excellent light resistance and fastness (Japanese Patent Laid-open Nos. 53565/1985, 18928-9/1988 and 182192/1988), but most of these dyestuffs lack both of a high sublimation speed and the stability of a transferred image. The development of dyestuffs which can meet the optimum requirements of sublimable dyestuffs has been sought.

SUMMARY OF THE INVENTION

The present inventors have intensively investigated to solve the above-mentioned problems, and as a result, have discovered that the sublimation rate of a dyestuff for heat-sensitive transfer record at the time of its transfer is connected with an interaction among the molecules of the dyestuff and another interaction between the molecules of the dyestuff and a binder resin for an ink.

That is, it has been made apparent that the best dyestuff has a good solubility in an ink solvent, a low melting point, and such a small interaction with the binder resin for the ink as not to impair the shelf stability of the dyestuff after the formation of a transfer sheet. Furthermore, it has been found that a compound represented by the formula (1) which will be described hereinafter is suitable for a yellow dyestuff for heat-sensitive transfer record. On the basis of this knowledge, the present invention has been completed.

In consequence, an object of the present invention is to provide a dyestuff for heat-sensitive transfer record, an ink composition for heat-sensitive transfer record and a transfer sheet which have a high sublimation rate and which permit transferring a stable image.

The present invention is directed to a dyestuff for heat-sensitive transfer record which comprises a compound represented by the formula (1) ##STR2## wherein R₁ is a hydrogen atom, alkyl group having 1 to 8 carbon atoms or cycloalkyl group; R₂ is a hydrogen atom, halogen atom, alkoxy group which may be substituted, alkylthio group which may be substituted or arylthio group which may be substituted; R₃ is a branched alkyl group having 3 to 5 carbon atoms, O-substituted oxycarbonyl group, N-substituted aminocarbonyl group in which an N-substituted group may form a ring, or substituted or unsubstituted heterocyclic ring having two or more hetero atoms of one or more kinds selected from the group consisting of a nitrogen atom, oxygen atom and sulfur atom; and when R₁ is a hydrogen atom, R₃ is a branched alkyl group having 3 to 5 carbon atoms, or substituted or unsubstituted heterocyclic ring having two or more hetero atoms of one or more kinds selected from the group consisting of a nitrogen atom, oxygen atom and sulfur atom.

Furthermore, the compound of the formula (1) can be present as a tautomer represented by the following formula (1'), but this tautomer is also within the category of the present invention: ##STR3##

The present invention is also directed to an ink composition for heat-sensitive transfer record which comprises a dyestuff for heat-sensitive transfer record represented by the formula (1), a binder resin, and an organic solvent and/or water.

Moreover, the present invention is directed to a transfer sheet which comprises a base sheet and a dyestuff-supporting layer formed all over the base sheet, the dyestuff contained in the dyestuff-supporting layer being the above-mentioned dyestuff.

BRIEF DESCRIPTION OF THE DRAWINGS

Each of FIGS. 1, 2 and 3 is a graph showing a relation between a reflective density of a recorded image and a dyestuff concentration in an ink, in the case that transfer record was carried out by applying energies of 3.58, 2.91 and 2.01 mJ/dot by means of a thermal head.

DETAILED DESCRIPTION OF THE INVENTION

In the present invention, a compound represented by the formula (1) is used as a dyestuff for heat-sensitive transfer record.

R₁ in the formula (1) is a hydrogen atom, alkyl group having 1 to 8 carbon atoms or cycloalkyl group.

Typical examples of the alkyl group include methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl and n-octyl groups.

Preferable examples of the cycloalkyl group are those having 5 to 6 carbon atoms, and typical examples thereof include cyclopentyl and cyclohexyl groups.

R₂ in the formula (1) is a hydrogen atom, halogen atom, alkoxy group which may be substituted, alkylthio group which may be substituted or arylthio group which may be substituted.

Preferable examples of the halogen atom include fluorine,, chlorine and bromine.

Preferable examples of the alkoxy which may be substituted are those having 1 to 6 carbon atoms, and typical examples thereof include methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, iso-butoxy and tert-butoxy.

Preferable examples of the alkylthio group which may be substituted are those having 1 to 4 carbon atoms, and typical examples thereof include methylthio, ethylthio, n-propylthio, iso-propylthio, n-butylthio and iso-butylthio.

Preferable examples of the arylthio group which may be substituted are phenylthio groups which may be substituted by an alkyl group having 1 to 4 carbon atoms, and typical examples thereof include o-methylphenylthio, m-methylphenylthio, p-methylphenylthio and p-tertbutylphenylthio.

R₃ is a branched alkyl group having 3 to 5 carbon atoms, O-substituted oxycarbonyl group, N-substituted aminocarbonyl group in which an N-substituted group may form a ring, or substituted or unsubstituted heterocyclic ring group having two or more hetero atoms of one or more kinds selected from the group consisting of a nitrogen atom, oxygen atom and sulfur atom, and when R₁ is a hydrogen atom, R₃ is a branched alkyl group having 3 to 5 carbon atoms, or substituted or unsubstituted heterocyclic ring group having two or more hetero atoms of one or more kinds selected from the group consisting of a nitrogen atom,, oxygen atom and sulfur atom.

Here, examples of the branched alkyl group having 3 to 5 carbon atoms include iso-propyl, iso-butyl, tert-butyl and iso-pentyl.

Preferable examples of the O-substituted oxycarbonyl group are those having 1 to 6 carbon atoms, and typical examples thereof include methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, iso-propoxycarbonyl, n-butoxycarbonyl, iso-butoxycarbonyl, tert-butoxycarbonyl, n-pentyloxycarbonyl and n-hexylcarbonyl groups.

Preferable examples of the N-substituted aminocarbonyl group are those having 1 to 10 carbon atoms, and typical examples thereof include methylaminocarbonyl, ethylaminocarbonyl, n-propylaminocarbonyl, iso-propylaminocarbonyl, n-butylaminocarbonyl, dimethyaminocarbonyl, diethylaminocarbonyl, di-n-propylaminocarbonyl, di-isopropylaminocarbonyl and di-n-butylaminocarbonyl.

Examples of the N-substituted aminocarbonyl group which forms a ring include carboxyl groups substituted by pyrrolidinyl, piperidino, 3,5-dimethylpiperidino, morpholino, piperazino, N-methylpiperazino, N-ethylpiperazino, N-n-propylpiperazino, N-iso-propylpiperazino, N-n-butylpiperazino, N-iso-butylpiperazino, N-tert-butylpiperazino, N-methoxyethylpiperazino, N-ethoxyethylpiperazino, N-n-propoxyethylpiperazino, N-iso-propoxyethylpiperazino, N-n-butoxyethylpiperazino, N-iso-butoxyethylpiperazino and N-tert-butoxyethylpiperazino.

Preferable examples of the substituted or unsubstituted heterocyclic ring group having two or more hetero atoms of one or more kinds selected from the group consisting of a nitrogen atom, oxygen atom and sulfur atom are substituted or unsubstituted compounds having a five-membered ring or six-membered ring, and typical examples of the substituent in the ring group include alkyl groups such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl and tert-butyl groups; alkoxy groups such as methoxy, ethoxy, n-propoxy and n-butoxy; alkylcarboxyalkyl groups such as methylcarboxymethyl, ethylcarboxymethyl, n-propylcarboxymethyl, iso-propylcarboxymethyl and n-butylcarboxymethyl; and alkoxycarboxyalkyl groups such as methoxycarboxymethyl, ethoxycarboxymethyl, n-propoxycarboxymethyl, iso-propoxycarboxymethyl and n-butoxycarboxymethyl. Typical examples of the substituted or unsubstituted compounds include oxazoline, oxazole, benzooxazole, thiazoline, thiazole, benzothiazole, imidazoline, imidazole, benzoimidazole, oxadiazole and thiadiazole.

R₁, R₂ and R₃ in the tautomer represented by the above-mentioned formula (1') are as defined above.

The dyestuff represented by the formula (1) can be obtained by combining 3-hydroxy-2-methyl-4-cinchonic acid with phthalic anhydride in accordance with a usual technique shown by the following reaction formula: ##STR4##

The introduction of a substituent into the 4-position of the thus obtained quinaphthalone can be achieved by substituting the 4-position by a usual electrophilic reagent, or alternatively first substituting the 4-position by a halogen and then substituting by a usual nucleophilic reagent.

In the present invention, an ink composition for heat-sensitive transfer record can be prepared by using the dyestuff obtained by the above-mentioned method, and so the dyestuff can be fed in the state of the ink.

The preparation of the ink composition for heat-sensitive transfer record by the use of the sublimable dyestuff of the present invention can be achieved by mixing the dyestuff with a suitable resin and solvent.

In this case, the amount of the dyestuff in the ink for heat-sensitive transfer record is preferably in the range of from 2 to 7% by weight.

The resin which can be used to prepare the ink is what is used in a usual printing ink, and examples of the resin include oil resins such as rosin, phenol, xylene, petroleum, vinyl, polyamide, alkyd, nitrocellulose and alkylcellulose resins, and aqueous resins such as maleic and acrylic resins, casein, shellac and glue.

Examples of the solvent for the preparation of the ink include alcohols such as reethanol, ethanol, propanol and butanol; cellosolves such as methyl cellosolve and ethyl cellosolve; aromatics such as benzene, toluene and xylene; esters such as ethyl acetate and butyl acetate; ketones such as acetone, methyl ethyl ketone and cyclohexanone; hydrocarbons such as ligroin, cyclohexane and kerosene; and dimethylformamide. In the case that the aqueous resin is used, water and a mixture of water and the above-mentioned solvent can be also used.

Examples of the base sheet which is coated with the ink include thin papers such as a condenser paper and glassine paper, and plastic films having good heat resistance such as a polyester, polyamide and polyimide. The thickness of this base sheet is suitably in the range of from 1 to 50 μm in order to improve the transfer efficiency of heat from a heat-sensitive record head to the dyestuff.

The dyestuff-supporting layer on the above-mentioned base sheet can be formed by coating the base sheet with the above-mentioned ink.

In the present invention, the dyestuff-supporting layer of the transfer sheet can be fundamentally formed from the above-mentioned material, but if necessary, the dyestuff-supporting layer can contain known various additives.

The thickness of the thus formed dyestuff-supporting layer is in the range of from 0.2 to 5.0 μm, preferably from 0.4 to 2.0 μm, and the dyestuff in the layer is preferably present in an amount of from 5 to 70% by weight, preferably from 10 to 60% by weight based on the weight of the layer.

The transfer sheet of the present invention is sufficiently useful in a heat transfer step, even if it is not additionally treated. However, an anti-tack layer, i.e., a release layer may be formed on the dyestuff-supporting layer. The formation of such a layer prevents the transfer sheet from adhering to the material to be recorded at the time of the heat transfer and permits using a high heat transfer temperature to form an image having a remarkably excellent density.

This release layer has a considerable effect, even if it is formed only by applying an anti-tack inorganic powder. Furthermore, a the release layer comprising a resin such as a silicone polymer, acrylic polymer or fluorinated polymer having excellent releasing properties and having a thickness of from 0.01 to 5 μm, preferably 0.05 to 2 μm can be formed.

Even when the above-mentioned inorganic powder or the release polymer is contained in the dyestuff-supporting layer, the sufficient effect can be obtained.

Examples of the material to be recorded include fibers, fabrics, films, sheets and molded articles made of polyolefin resins such as polyethylene and polypropylene; halogenated polymers such as polyvinyl chloride and polyvinylidene chloride; vinyl polymers such as polyvinyl alcohol, polyvinyl acetate and polyacrylic ester; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polystyrene resins; polyamide resins, copolymer resins of olefins such as ethylene and propylene and other vinyl monomers; ionomers; cellulose resins such as cellulose diacetate and cellulose triacetate; polycarbonate; polysulfone and polyimide.

Particularly preferable are fabrics, sheets and films made of polyethylene terephthalate.

In addition, as the above-mentioned materials to be recorded, there can also be used papers coated and laminated with a mixture of the above-mentioned resin and acidic particles such as silica gel, papers laminated with resin films, and specific converted papers subjected to acetylation. The employment of such papers results in a good record having an excellent image stability at high temperature and high humidity. Moreover, films of various resins and synthetic papers made thereof can also be used.

Additionally, in order to prevent a bad influence due to the heat of the thermal head, a heat-resistant layer may be formed on the back surface of the transfer sheet.

As the material to be recorded which can be employed to form the image by the use of the above-mentioned transfer sheet, any one can be utilized, so long as the record surface of the material has dyestuff receiving properties for the above-mentioned dyestuff. Furthermore, when a paper, metal, glass or synthetic resin which does not have the dyestuff receiving properties is used, at least one surface of such a material should be formed with a dyestuff receiving layer.

The heat transfer can be achieved by superposing the sheet upon the material to be recorded, and then heating and pressing the sheet from its back surface by means of a heat-sensitive record head, whereby the dyestuff on the sheet can be transferred onto the material to be recorded.

In carrying out the heat transfer by the use of the transfer sheet of the present invention and the above-mentioned material to be recorded, as a means for giving heat energy to the transfer sheet, there can be used any of known conventional means. For example, a recording device such as a thermal printer (e.g., Video Printer-VY-100, made by Hitachi, Ltd.) can be used to control a recording time, so that a heat energy of from 5 to 100 mj/mm³ can be given, whereby the predetermined object can be sufficiently achieved.

After the transfer record step, for example, a polyester film is thermally pressed on a transfer record surface to laminate the film thereon, whereby the color development of the dyestuff can be improved and the record can be stably preserved.

With regard to the yellow sublimable dyestuff represented by the formula (1) of the present invention, the sublimation transfer amount of the dyestuff can be controlled by changing the energy given to the heat-sensitive head at the time of the heat transfer, and therefore the gradation record can be easily achieved. Thus, the yellow sublimable dyestuff is suitable for the full color record.

In addition, the yellow sublimable dyestuff is stable to heat, light, humidity and chemicals, and it does not thermally decompose during the transfer record. The shelf stability of the obtained record is also excellent.

The dyestuff of the present invention is excellent in solubility in the organic solvent and dispersion in water, and so it is easy to prepare the highly concentrated and uniformly dissolved or dispersed ink. In consequence, the record having a high color density can be obtained. It is sure that the dyestuff of the formula (1) is practically valuable.

Now, the present invention will be described in detail in reference to examples. In these examples, "part(s)" and "%" are on weight.

EXAMPLE 1

A compound represented by the formula (A) was prepared as follows.

10.2 parts of 5-tert-butylphthalic anhydride and 10.2 parts of 3-hydroxy-2-methylquinoline-4-carboxylic acid were added to 150 parts of sulfolane, and reaction was then carried out at 195° C. for 1 hour to obtain 18 parts by a compound of the formula (A).

Furthermore, by the use of the compound of the formula (A), an ink composition, a transfer sheet and a material to be recorded were prepared in accordance with the following procedures, and transfer record was then carried out.

The absorption maximum wavelength (? ,max) of the compound in chloroform was 445 nm. ##STR5##

(1) Preparation of ink composition

    ______________________________________                                         Dyestuff of the formula (A)                                                                           3 parts                                                 Polyvinylbutyral resin 4.5 parts                                               Methyl ethyl ketone    46.25 parts                                             Toluene                46.25 parts                                             ______________________________________                                    

The above-mentioned composition including the dyestuff was mixed for about 30 minutes with a paint conditioner by the use of glass beads to prepare an ink.

(2) Preparation of transfer sheet

The thus prepared ink was applied on a polyethylene terephthalate film having a thickness of 6 μm and a back surface subjected to a heat resistance treatment by a gravure calibrator (thickness 30 μm) so that the dry weight of the ink might be 1.0 g/m², and the ink was then dried.

(3) Preparation of material to be recorded

    ______________________________________                                         Polyester resin            0.8    part                                         (Vylon 103, made by Toyobo Co., Ltd.,                                          Tg = 47° C.)                                                            EVA polymeric plasticizer  0.2    part                                         (Eruvaroi 741P, made by Mitsui                                                 Polychemical Co., Ltd., Tg = 37° C.)                                    Amino-modified silicone    0.04   part                                         (KF-857, made by The Sin-Etus Chemical Co.,                                    Ltd.)                                                                          Epoxy-modified silicone    0.04   part                                         (KF-103, made by The Sin-Etus Chemical Co.,                                    Ltd.)                                                                          Methyl ethyl ketone/toluene/cyclohexane                                                                   9.0    parts                                        (weight ratio 4:4:2)                                                           ______________________________________                                    

The above-mentioned composition was mixed to form a coating solution. This coating solution was then applied onto a synthetic paper (Yupo FPG #150, made by Oji Yuka Co., Ltd.) by means of a bar coater (No. 1, made by RK. Print Cort Instruments Co., Ltd.) so that the dry weight of the coating solution might be 4.5 g/m², and it was then dried at 100° C. for 15 minutes.

(4) Transfer record

The above-mentioned transfer sheet was superposed upon the material to be recorded so that the ink-applied surface might be brought into contact with the coating solution-applied surface, and recording was then carried out under conditions of a heat-sensitive head application voltage of 11 V and a printing time of 16.0 milliseconds by heating the heat transfer sheet from its back surface, thereby recording a yellow color having a color density of 2.00.

This color density was measured by the use of a densitometer RD-514 type (filter: latten No. 58) made by U.S. Macbeth Co., Ltd.

The color density was calculated in accordance with the following formula.

    ______________________________________                                         Color density =                                                                             log.sub.10 (I.sub.0 /I)                                           Io =         Intensity of reflected light from a                                            standard white reflector plate                                    I =          Intensity of reflected light from a test                                       piece.                                                            ______________________________________                                    

For the obtained record, a light resistance test was made at a black panel temperature of 63°±2° C. for 40 hours by the use of a xenon fade meter (made by Suga Tester Co., Ltd.). As a result, the record scarcely changed, and the stability of the image at a high temperature and a high humidity was also excellent.

The fastness of the recorded image was evaluated by allowing the image to stand in an atmosphere at 50° C. for 48 hours, and then observing the sharpness of the image and a coloring state on a white paper by which the image was rubbed. As a result, the sharpness of the image did not change and the white paper was not colored, which meant that the fastness of the recorded image was good.

EXAMPLE 2

The following compound (C) was prepared by the undermentioned procedure.

21.1 parts of trimellitic anhydride were added to 285 parts of sulfolane, and the solution was then heated up to 185° C. Next, 24.6 parts of 3-hydroxy-2-methyl-6-iso-propylquinoline-4-carboxylic acid were further added thereto, and reaction was then carried out at 200° C. for 1 hour to obtain 37.2 parts of a compound of the following formula (B) which was the precursor of the desired product. ##STR6##

3 parts of the compound having the formula (B), 0.1 part of KI and 1. 5 parts of K₂ CO₃ were added to 50 parts of DMF, and the solution was then heated up to 80° C. Afterward, 5.4 parts of n-amyl tosylate were added thereto, and reaction was then carried out at 150° C. for 3 hours to obtain 4.2 parts of the compound represented by the formula (C). The absorption maximum wavelength (Kmax) of the compound in toluene was 452 nm. ##STR7##

In accordance with the same procedure as in Example 1, an ink, a transfer sheet and a material to be recorded were prepared, and transfer record was then carried out, to obtain a yellow record having a color density of 1.95.

For this record, a light resistance test was made in the same manner as in Example 1, and as a result, the record scarcely changed and the stability of the image at a high temperature and a high humidity was also excellent.

For the recorded image, a fastness test was made in the same manner as in Example 1, but as a result, the sharpness of the image did not change and a white paper was not colored, which meant that the fastness of the recorded image was good.

EXAMPLES 3 to 21

In accordance with the same procedure as in Example 1, yellow dyestuffs shown in Table 1, inks, transfer sheets and materials to be recorded were prepared, and transfer record was then performed to obtain records shown in Table 1.

For these records, a light resistance test was made in the same manner as in Example 1, and as a result, the records scarcely changed, and the stability of the images at a high temperature and a high humidity was also excellent.

For these recorded images, a fastness test was made in the same manner as in Example 1, but as a result, the sharpness of the images did not change and a white paper was not colored, which meant that the fastness of the recorded images was good.

                                      TABLE 1                                      __________________________________________________________________________                                              Maximum                                                                        Optical                                                                               Light Fastness of the          Example                                                                              Structural Formula                 Density                                                                               Resistance                                                                           Recorded                 __________________________________________________________________________                                                           Image                     3                                                                                    ##STR8##                          1.90   ◯                                                                        ◯             4                                                                                    ##STR9##                          1.90   ◯                                                                        ◯             5                                                                                    ##STR10##                         2.00   ◯                                                                        ◯              6                                                                                   ##STR11##                         1.85   ◯                                                                        ◯             7                                                                                    ##STR12##                         1.90   ◯                                                                        ◯             8                                                                                    ##STR13##                         1.80   ◯                                                                        ◯             9                                                                                    ##STR14##                         1.85   ◯                                                                        ◯            10                                                                                    ##STR15##                         1.86   ◯                                                                        ◯            11                                                                                    ##STR16##                         1.85   ◯                                                                        ◯            12                                                                                    ##STR17##                         1.90   ◯                                                                        ◯            13                                                                                    ##STR18##                         1.90   ◯                                                                        ◯            14                                                                                    ##STR19##                         1.90   ◯                                                                        ◯            15                                                                                    ##STR20##                         1.90   ◯                                                                        ◯            16                                                                                    ##STR21##                         1.85   ◯                                                                        ◯            17                                                                                    ##STR22##                         1.85   ◯                                                                        ◯            18                                                                                    ##STR23##                         1.88   ◯                                                                        ◯            19                                                                                    ##STR24##                         1.85   ◯                                                                        ◯            20                                                                                    ##STR25##                         1.76   ◯                                                                        ◯            21                                                                                    ##STR26##                         1.66   ◯                                                                        ◯            __________________________________________________________________________

With regard to the evaluated results of the light resistance and the fastness of the recorded image, the good results were denoted by o and the bad results by x.

COMPARATIVE EXAMPLES 1 to 4

The results of Comparative Examples 1 to 4 are set forth in Table 2.

                                      TABLE 2                                      __________________________________________________________________________                                     Maximum                                        Comparative                     Optical                                                                              Light Fastness of the                    Example                                                                               Structural Formula       Density                                                                              Resistance                                                                           Recorded Image                     __________________________________________________________________________             ##STR27##               1.10  ◯                                                                        ◯                      2                                                                                      ##STR28##               0.70  ◯                                                                        ◯                      3      C.I. Solvent Yellow 56   1.75  x     x                                  4      C.I. Disperse Yellow 3   1.65  x     x                                  __________________________________________________________________________      ◯: The sharpness of the image did not change, and a white          paper was not colored.                                                         x: The image was unclear and a white paper was noticeably colored.       

EXAMPLE 22 AND COMPARATIVE EXAMPLE 5

An ink composition of the following components was prepared and then allowed to stand a whole day and night. The thus prepared ink was applied on a polyethylene terephthalate film having a thickness of 6 μm and a back surface subjected to a heat resistance treatment so that the dry weight of the ink might be 1.0 g/m², and the ink was then dried to obtain a transfer sheet.

    ______________________________________                                         Compound (dyestuff) of (D) or (E)                                                                    5        parts                                           Polyvinylbutyral resin                                                                               4.5      parts                                           Methyl butyl ketone   46.25    parts                                           Toluene               46.25    parts                                           ______________________________________                                          ##STR29##                                                                      ##STR30##                                                                

Next, a coating solution having the following composition was applied onto (1) a synthetic paper (Yupo FPG #150, made by Oji Yuka Co., Ltd.) or (2) a transparent polyethylene terephthalate film having a thickness of 100 μm as a base sheet so that the dry weight of the coating solution might be 10.0 g/m², and it was then dried at 100° C. for 30 minutes to obtain a material to be transferred.

    ______________________________________                                         Polyester resin           11.5 parts                                           (Vylon 200, made by Toyobo Co., Ltd.)                                          Vinyl chloride.vinyl acetate                                                                             5.0 parts                                            copolymer 1000A (Denki Kagaku Kogyo K.K.)                                      Amino-modified silicone KF-393                                                                           1.2 parts                                            (The Sin-Etus Chemical Co., Ltd.)                                              Epoxy-modified silicone X-22-343                                                                         1.2 parts                                            (The Sin-Etus Chemical Co., Ltd.)                                              Methyl ethyl ketone/toluene/cyclohexane                                                                  102.0 parts                                          (weight ratio 4:4:2)                                                           ______________________________________                                    

The above-mentioned transfer sheet was superposed upon the material to be recorded so that the ink-applied surface might be brought into contact with the coating solution-applied surface, and recording was then carried out under conditions of a heat-sensitive head application voltage of 11 V in the case of the base sheet (1) and 12 V in the case of the base sheet (2) by heating the heat transfer sheet from its back surface by the use of a thermal head made by Kyoto Ceramic Co., Ltd. (KMT-85-6MPD2-HIV; resistance 500 ohm). In addition, the stability of the ink and the roughness of the transferred image were inspected. The obtained results are set forth in Table 3.

An image density was measured by the use of a transmission/reflection densitometer X-Rite 310TR (X-Rite Co., Ltd.).

The results are set forth in Table 3.

                  TABLE 3                                                          ______________________________________                                                                Comparative                                                         Example 22 Example 5                                               ______________________________________                                             Dyestuff      Compound (D) Compound (E)                                        Base Sheet                                                                 (1) Reflective    1.95         1.55                                                Density                                                                    (2) Transmissive  1.68         1.23                                                Density                                                                        Stability of Ink                                                                             Dyestuff was Undissolved                                                       completely   dyestuff was                                                      dissolved.   deposited.                                          State of      Good image   Image was soiled                                    Transferred   was obtained.                                                                               by dye deposited                                    Image                      on transfer                                                                    sheet, and                                                                     image density                                                                  deteriorated.                                   ______________________________________                                    

EXAMPLE 23 AND COMPARATIVE EXAMPLE 6 ##STR31##

An ink composition of the following components was heated up to 70° C. to completely dissolve the same. Next, this ink was allowed to stand at room temperature (25° C.) for 48 hours, and the ink was then applied on a polyethylene terephthalate film having a thickness of 6 μm and a back surface subjected to a heat resistance treatment so that the dry weight of the ink might be 1.0 g/m², and the ink was then dried to obtain a transfer sheet.

    ______________________________________                                         Ink composition                                                                ______________________________________                                         Dyestuff F             a parts                                                 (Example 23) or (Comp. Example 6)                                              Polyvinylbutyral resin 4.5 parts                                               (BX-1, Sekisui Chemical Co., Ltd.)                                             Toluene                (95.5-a)/2 parts                                        Methyl ethyl ketone    (95.5-a)/2 parts                                        ______________________________________                                    

Next, a coating solution having the following composition was then applied onto one surface of a synthetic paper (Yupo FPG 150 μm, made by Oji Yuka Co., Ltd.) as a base sheet by means of a bar coater so that the dry weight of the coating solution might be 5.0 g/m², and immediately it was simply dried by a dryer and further dried at 80° C. for 5 minutes in an oven to obtain a material to be recorded.

    ______________________________________                                         Polyester resin           4.0    parts                                         (Vylon 600, made by Toyobo Co., Ltd.)                                          Vinyl chloride/vinyl acetate                                                                             6.0    parts                                         copolymer (1000A, Denki Kagaku Kogyo K.K.)                                     Amino-modified silicone   0.2    part                                          (X-22-8050C, The Sin-Etus Chemical Co., Ltd.)                                  Epoxy-modified silicone   0.2    part                                          (X-22-8000E, The Sin-Etus Chemical Co., Ltd.)                                  Methyl ethyl ketone/toluene/cyclohexane                                                                  89.6   parts                                         (weight ratio 1/1)                                                             ______________________________________                                    

The above-mentioned transfer sheet was superposed upon the material to be recorded so that the ink-applied surface might be brought into contact with the coating solution-applied surface, and heat transfer record was then carried out under conditions of a heat-sensitive head application voltage of 10.75 V and application energies of 8.58, 2.91 and 2.01 mi/dot by the use of a thermal head made by Kyoto Ceramic Co., Ltd. (KMT-85-6MPD2-HTV; resistance 500 ohm). The results are shown in Tables 4 and 5 as well as FIGS. 1, 2 and 3.

                  TABLE 4                                                          ______________________________________                                         (Dyestuff F) (Example)                                                         ______________________________________                                                     Melting State                                                                  of Dyestuff                                                        Dyestuff Conc.                                                                             after Standing Surface State of                                    in Ink (wt %)                                                                              for 48 hours   Transfer Sheet                                      ______________________________________                                         1.0         Completely dissolved                                                                          Lustrous                                            2.0         Completely dissolved                                                                          Lustrous                                            2.2         Completely dissolved                                                                          Lustrous                                            2.4         Completely dissolved                                                                          Lustrous                                            2.6         Completely dissolved                                                                          Lustrous                                            2.8         Completely dissolved                                                                          Lustrous                                            3.0         Completely dissolved                                                                          Lustrous                                            3.2         Completely dissolved                                                                          Lustrous                                            3.4         Completely dissolved                                                                          Lustrous                                            3.6         Completely dissolved                                                                          Lustrous                                            4.0         Completely dissolved                                                                          Lustrous                                            5.0         Completely dissolved                                                                          Lustrous                                            6.0         Completely dissolved                                                                          Lustrous                                            7.0         Completely dissolved                                                                          Lustrous                                            ______________________________________                                         Dyestuff Conc.  Image Density (reflection)                                     in Ink (wt %)                                                                            3.58 mj/dot  2.91 mj/dot                                                                              2.01 mj/dot                                   ______________________________________                                         1.0       1.14         0.86      0.48                                          2.0       1.57         1.19      0.64                                          2.2       1.68         1.21      0.65                                          2.4       1.70         1.26      0.68                                          2.6       1.74         1.30      0.70                                          2.8       1.77         1.96      0.71                                          3.0       1.82         1.39      0.74                                          3.2       1.86         1.42      0.78                                          3.4       1.88         1.44      0.78                                          3.6       1.91         1.46      0.74                                          4.0       1.94         1.51      0.81                                          5.0       2.05         1.60      0.89                                          6.0       2.12         1.72      0.91                                          7.0       2.18         1.80      0.95                                          ______________________________________                                    

The dyestuff (F) could be dissolved in the ink even at a concentration of 7%, and the printing density of the transfer sheets, in which the dyestuff was used, were not saturated even under the respective application energies (8.58. 2.91 and 2.01 mJ/dot) and were liable to increase.

Furthermore, the surface state of the transfer sheets was lustrous, because the dyestuff was dissolved in the binder, and after the transfer, good images could be transferred on the materials to be recorded.

                  TABLE 5                                                          ______________________________________                                         (Dyestuff G) (Comparative Example)                                             ______________________________________                                                    Dissolution                                                                    of Dyestuff                                                         Dyestuff Conc.                                                                            after Standing   Surface State of                                   in Ink (wt %)                                                                             for 48 hours     Transfer Sheet                                     ______________________________________                                         1.0        Completely dissolved                                                                            Lustrous                                           2.0        Completely dissolved                                                                            Lustrous                                           2.2        Completely dissolved                                                                            Lustrous                                           2.4        Completely dissolved                                                                            Lustrous                                           2.6        Completely dissolved                                                                            Lustrous                                           2.8        Very slightly deposited                                                                         Lustrous                                           3.0        Slightly deposited                                                                              Rough                                              3.2        Abundantly deposited                                                                            Rough                                              3.4        Abundantly deposited                                                                            Rough                                              3.6        Abundantly deposited                                                                            Rough                                              4.0        Abundantly deposited                                                                            Rough                                              5.0        Abundantly deposited                                                                            Rough                                              6.0        Abundantly deposited                                                                            Rough                                              7.0        Abundantly deposited                                                                            Rough                                              ______________________________________                                         Dyestuff Conc.  Image Density (reflection)                                     in Ink (wt %)                                                                            3.58 mj/dot  2.91 mj/dot                                                                              2.01 mj/dot                                   ______________________________________                                         1.0       1.16         0.88      0.48                                          2.0       1.60         1.22      0.86                                          2.2       1.65         1.25      0.67                                          2.4       1.73         1.32      0.71                                          2.6       1.77         1.35      0.71                                          2.8       1.80         1.40      0.74                                          3.0       1.71         1.29      0.69                                          3.2       1.72         1.28      0.66                                          3.4       1.65         1.22      0.64                                          3.6       1.68         1.24      0.65                                          4.0       1.57         1.12      0.57                                          5.0       1.57         1.12      0.55                                          6.0       1.51         1.06      0.58                                          7.0       1.48         0.99      0.52                                          ______________________________________                                    

In the vicinity of a concentration of about 2.8% the deposition of the dyestuff was observed in the ink, and after the coating, the surfaces of the transfer sheets began to be roughened under the influence of the undissolved dyestuff.

In any case of the respective application energies, the maximum image concentration was present at a dyestuff concentration of 2.8% in the ink, and when the dyestuff concentration was 8% or more, the image concentrations did not increase any more or deteriorated.

After the transfer, the image receiving sheets were soiled owing to the rough surfaces thereof.

As is apparent from the results of this comparative example, the compound (F) in which an isopropyl group was introduced into a quinoline ring of the compound (G) could be sufficiently dissolved in the ink, and therefore the high image concentrations could be obtained.

EXAMPLE 24 AND COMPARATIVE EXAMPLE 7

An ink composition of the following components was prepared and then allowed to stand a whole day and night. The thus prepared ink was applied on a polyethylene terephthalate film having a thickness of 6 μm and a back surface subjected to a heat resistance treatment so that the dry weight of the ink might be 1.0 g/m², and the ink was then dried to obtain a transfer sheet.

    ______________________________________                                         The ink composition for the transfer sheet                                     ______________________________________                                         Compound (dyestuff)     5       parts                                          (H: Example 24 or I: Comp. Example 7)                                          Vinyl chloride/vinyl acetate                                                                           10      parts                                          copolymer                                                                      Methyl ethyl ketone     42.5    parts                                          Toluene                 42.5    parts                                          ______________________________________                                          ##STR32##                                                                      ##STR33##                                                                

Next, a coating solution having the following composition was applied onto (1) a synthetic paper (Yupo FPG #150, made by Oji Yuka Co., Ltd.) or (2) a transparent polyethylene terephthalate film having a thickness of 100 μm as a base sheet so that the dry weight of the coating solution might be 10.0 g/m², and it was then dried at 100° C. for 30 minutes to obtain a material to be transferred.

    ______________________________________                                         Polyester resin           11.5 parts                                           (Vylon 200, made by Toyobo Co., Ltd.)                                          Vinyl chloride.vinyl acetate                                                                             5.0 parts                                            copolymer 1000A (Denki Kagaku Kogyo K.K.)                                      Amino-modified silicone KF-393                                                                           1.2 parts                                            (The Sin-Etus Chemical Co., Ltd.)                                              Epoxy-modified silicone X-22-343                                                                         1.2 parts                                            (The Sin-Etus Chemical Co., Ltd.)                                              Methyl ethyl ketone/toluene/                                                                             102.0 parts                                          cyclohexane (weight ratio 4:4:2)                                               ______________________________________                                    

The above-mentioned transfer sheet was superposed upon the material to be recorded so that the ink-applied surface might be brought into contact with the coating solution-applied surface, and a transfer operation was then carried out under conditions of an application voltage of 11 V in the case of the base sheet (1) and 12 V in the case of the base sheet (2) by heating the transfer sheet from its back surface by the use of a thermal head made by Kyoto Ceramic Co., Ltd. (KMT-85-6MPD2-HTV; resistance 500 ohm). In addition, the stability of the ink and the roughness of the transferred image were inspected. The obtained results are set forth in Table 6.

An image density was measured by the use of a transmission/reflection densitometer X-Rite 310TR (X-Rite Co., Ltd.).

                  TABLE 6                                                          ______________________________________                                                     Dyestuff                                                                       Compound (H)                                                                              Compound (I)                                                        (Example 24)                                                                              (Comp. Ex. 7)                                           ______________________________________                                               Base Sheet                                                               (1)   Reflective  1.81         1.57                                                  Density                                                                  (2)   Transmissive                                                                               1.01         0.70                                                  Density                                                                        Stability   Dyestuff was Undissolved                                           of Ink      completely   dyestuff was                                                      dissolved.   precipitated.                                                                  Amount of                                                                      precipitated                                                                   dyestuff was                                                                   55% of                                                                         initial feed.                                         State of    Good image   Image was                                             Transferred was          soiled with                                           Image       obtained.    precipitated                                                                   dyestuff, and                                                                  image density                                                                  deteriorated.                                   ______________________________________                                    

EXAMPLE 25

A compound represented by the following formula (K) was prepared by the undermentioned procedure.

53.8 parts of trimellitic anhydride and 50.8 parts of 3-hydroxy-2-methylquinoline-4-carboxylic acid were added to 538 parts of sulfolane, and reaction was then carried out at 200° C. for 1 hour to obtain 68 parts of a compound of the following formula (J) which was the precursor of the desired product. ##STR34##

10 parts of the compound having the formula (J) and 0.4 part of pyridine were added to 60 parts of o-dichlorobenzene, and the solution was then heated up to 100° C. Afterward, 7.2 parts of thionyl chloride were added thereto, and reaction was then carried out at 100° C. for 2 hours. Afterward, excessive thionyl chloride was removed at 100° C. under reduced pressure, and 3.4 parts of 3-amino-2-propanol were added, followed by reaction at 100° C. for 1 hour. Furthermore, the solution was heated up to 170° C., and reaction was then carried out for 7 hours to obtain 9.5 parts of the compound represented by the formula (K). The absorption maximum wavelength (? ,max) of this compound in toluene was 448 nm. ##STR35##

(1) Preparation of ink composition

    ______________________________________                                         Dyestuff of the formula (K)                                                                           3 parts                                                 Polyvinylbutyral resin 4.5 parts                                               Methyl ethyl ketone    46.25 parts                                             Toluene                46.25 parts                                             ______________________________________                                    

The above-mentioned composition including the dyestuff was mixed for about 30 minutes with a paint conditioner by the use of glass beads to prepare an ink.

(2) Preparation of transfer sheet

The thus prepared ink was applied on a polyethylene terephthalate film having a thickness of 6 μm and a back surface subjected to a heat resistance treatment by a gravure calibrator (thickness 30 Km) so that the dry weight of the ink might be 1.0 g/m², and the ink was then dried.

(3) Preparation of material to be recorded

    ______________________________________                                         Polyester resin            0.8    part                                         (Vylon 103, made by Toyobo Co., Ltd.,                                          Tg = 47° C.)                                                            EVA polymeric plasticizer  0.2    part                                         (Eruvaroi 741p, made by Mitsui Polychemical                                    Co., Ltd., Tg = 37° C.)                                                 Amino-modified silicone    0.04   part                                         (KF-857, made by The Sin-Etus Chemical Co.,                                    Ltd.)                                                                          Epoxy-modified silicone    0.04   part                                         (KF-103, made by The Sin-Etus Chemical Co.,                                    Ltd.)                                                                          Methyl ethyl ketone/toluene/cyclohexane                                                                   9.0    parts                                        (weight ratio 4:4:2)                                                           ______________________________________                                    

The above-mentioned composition was mixed to form a coating solution. This coating solution was then applied onto a synthetic paper (Yupo FPG #150, made by Oji Yuka Co., Ltd.) by means of a bar coater (No. 1, made by RK. Print Cort Instruments Co., Ltd.) so that the dry weight of the coating solution might be 4.5 g/m², and it was then dried at 100° C. for 15 minutes.

(4) Transfer record

The above-mentioned transfer sheet was superposed upon the material to be recorded so that the ink-applied surface might be brought into contact with the coating solution-applied surface, and a transfer operation was then carried out under conditions of a heat-sensitive head application voltage of 11 v and a printing time of 16.0 milliseconds by heating the heat transfer sheet from its back surface, thereby recording a yellow color having a color density of 1.95.

This color density was measured by the use of a densitometer RD-514 type (filter: latten No. 58) made by U.S. Macbeth Co., Ltd.

The color density was calculated in accordance with the following formula.

    ______________________________________                                         Color density =                                                                             log.sub.10 (I.sub.0 /I)                                           I.sub.0 =    Intensity of reflected light from a                                            standard white reflector plate                                    I =          Intensity of reflected light from a test                                       piece.                                                            ______________________________________                                    

For the obtained record, a light resistance test was made at a black panel temperature of 63°±2° C. for 40 hours by the use of a xenon fade meter (made by Suga Tester Co., Ltd.). As a result, the record scarcely changed, and the stability of the image at a high temperature and a high humidity was also excellent.

The fastness of the recorded image was evaluated by allowing the image to stand in an atmosphere at 50° C. for 48 hours, and then observing the sharpness of the image and a coloring state on a white paper by which the image was rubbed. As a result, the sharpness of the image did not change and the white paper was not colored, which meant that the fastness of the recorded image was good.

EXAMPLE 26

A compound represented by the formula (L) was prepared as follows.

10 parts of a compound having the formula (J) and 0.4 part of pyridine were added to 50 parts of nitrobenzene, and the solution was then heated up to 100° C. Afterward, 7.2 parts of thionyl chloride were added thereto, and reaction was then carried out at 100° C. for 2 hours. Afterward, excessive thionyl chloride was removed at 100° C. under reduced pressure, and 4.6 parts of isopropylcarbonylhydrazine were added, followed by reaction for 1 hour. Next, 14.3 parts of thionyl chloride were further added, and the solution was then heated up to 130° C. and reaction was carried out for 4 hours to obtain 7.9 parts of a compound represented by the formula (L). The absorption maximum wavelength (Kmax) of this compound in toluene was 446 nm. ##STR36##

In accordance with the same procedures as in Example 25, an ink, a transfer sheet and a material to be recorded were prepared, and transfer record was then carried out to obtain a yellow record having a color density of 1.80.

For this record, a light resistance test was made in the same manner as in Example 25, and as a result, the record scarcely changed and the stability of the image at a high temperature and a high humidity was also excellent.

For the recorded image, a fastness test was made in the same manner as in Example 25, but as a result, the sharpness of the image did not change and a white paper was not colored, which meant that the fastness of the recorded image was good.

EXAMPLE 27 TO 58

In accordance with the same procedure as in Example 25 or 26, yellow dyestuffs shown in Table 7, inks, transfer sheets and materials to be recorded were prepared, and transfer record was then performed to obtain records shown in Table 7.

For these records, a light resistance test was made in the same manner as in Example 25, and as a result, the records scarcely changed, and the stability of the images at a high temperature and a high humidity was also excellent.

For the recorded images, a fastness test was made in the same manner as in Example 25, but as a result, the sharpness of the images did not change and a white paper was not colored, which meant that the fastness of the recorded images was good.

The measured results of the maximum transfer concentration, and the evaluated results of the light resistance and the fastness of the recorded image are set forth in Table 7.

                                      TABLE 7                                      __________________________________________________________________________                                                               Fastness                                                             Maximum                                                                              Light                                                                              of the               Exam-                                           Optical                                                                              Resis-                                                                             Recorded             ple Structural Formula                          Density                                                                              tance                                                                              Image                __________________________________________________________________________     27                                                                                  ##STR37##                                  1.85  ◯                                                                      ◯        28                                                                                  ##STR38##                                  1.90  ◯                                                                      ◯        29                                                                                  ##STR39##                                  1.92  ◯                                                                      ◯        30                                                                                  ##STR40##                                  1.90  ◯                                                                      ◯        31                                                                                  ##STR41##                                  1.80  ◯                                                                      ◯        32                                                                                  ##STR42##                                  1.85  ◯                                                                      ◯        33                                                                                  ##STR43##                                  1.90  ◯                                                                      ◯        34                                                                                  ##STR44##                                  1.85  ◯                                                                      ◯        35                                                                                  ##STR45##                                  1.92  ◯                                                                      ◯        36                                                                                  ##STR46##                                  1.90  ◯                                                                      ◯        37                                                                                  ##STR47##                                  1.80  ◯                                                                      ◯        38                                                                                  ##STR48##                                  1.85  ◯                                                                      ◯        39                                                                                  ##STR49##                                  1.85  ◯                                                                      ◯        40                                                                                  ##STR50##                                  1.84  ◯                                                                      ◯        41                                                                                  ##STR51##                                  1.85  ◯                                                                      ◯        42                                                                                  ##STR52##                                  1.90  ◯                                                                      ◯        43                                                                                  ##STR53##                                  1.85  ◯                                                                      ◯        44                                                                                  ##STR54##                                  1.90  ◯                                                                      ◯        45                                                                                  ##STR55##                                  1.88  ◯                                                                      ◯        46                                                                                  ##STR56##                                  1.91  ◯                                                                      ◯        47                                                                                  ##STR57##                                  1.95  ◯                                                                      ◯        48                                                                                  ##STR58##                                  1.90  ◯                                                                      ◯        __________________________________________________________________________

With regard to the evaluated results of the light resistance and the fastness of the recorded image, the good results were denoted by o and the bad results by x.

COMPARATIVE EXAMPLES 8 TO 11

Inks, transfer sheets and materials to be recorded were prepared in accordance with the same procedure as in Example 25 by the use of yellow dyestuffs shown in Table 8, and transfer record was then carried out. Furthermore, a light resistance test and a fastness test were also carried out in the same manner as in Example 25. As a result, products which could simultaneously meet the requirements of the maximum transfer density, the light resistance and the fastness of the recorded image could not be obtained, and images were unclear and white paper were noticeably colored, which meant that these products were poor.

                                      TABLE 8                                      __________________________________________________________________________     (Comparative Examples)                                                                                       Maximum                                                                        Optical                                                                              Light Fastness of the                      Example                                                                             Structural Formula       Density                                                                              Resistance                                                                           Recorded Image                       __________________________________________________________________________      8                                                                                   ##STR59##               1.0   ◯                                                                        ◯                         9                                                                                   ##STR60##               0.7   ◯                                                                        ◯                        10   C.I. Solvent Yellow-56   1.75  x     x                                    11   C.I. Disperse Yellow-3   1.65  x     x                                    __________________________________________________________________________

With regard to the evaluated results of the light resistance and the fastness of the recorded image, the good results were denoted by o and the bad results by x.

EXAMPLE 49

A compound represented by the following formula (M) was prepared by the undermentioned procedure.

10 parts of the compound having the formula (B) and 0.4 part of pyridine were added to 60 parts of o-dichlorobenzene, and the solution was then heated up to 100° C. Afterward, 7.2 parts of thionyl chloride were added thereto, and reaction was then carried out at 100° C. for 2 hours. Afterward, excessive thionyl chloride was removed at 100° C. under reduced pressure, and 10.4 parts of morpholine were added, followed by reaction at 100° C. for 2 hours, to obtain 10.5 parts of the compound represented by the formula (M). The absorption maximum wavelength (Mmx) of this compound in toluene was 446 nm. ##STR61##

(1) Preparation of ink

    ______________________________________                                         Dyestuff of the formula (M)                                                                           3 parts                                                 Polyvinylbutyral resin 4.5 parts                                               Methyl ethyl ketone    46.25 parts                                             Toluene                46.25 parts                                             ______________________________________                                    

The above-mentioned composition including the dyestuff was mixed for about 30 minutes with a paint conditioner by the use of glass beads to prepare an ink.

(2) Preparation of transfer sheet

The thus prepared ink was applied on a polyethylene terephthalate film having a thickness of 9 μm and a back surface subjected to a heat resistance treatment by a gravure calibrator (thickness 30 μm) so that the dry weight of the ink might be 1.0 g/m², and the ink was then dried.

(3) Preparation of material to be recorded

    ______________________________________                                         Polyester resin            0.8    part                                         (Vylon 103, made by Toyobo Co., Ltd.,                                          Tg = 47° C.)                                                            EVA polymeric plasticizer  0.2    part                                         (Eruvaroi 741p, made by Mitsui Polychemical                                    Co., Ltd., Tg = 37° C.)                                                 Amino-modified silicone    0.04   part                                         KF-857, made by The Sin-Etus Chemical Co.,                                     Ltd.)                                                                          Epoxy-modified silicone    0.04   part                                         (KF-103, made by The Sin-Etus Chemical Co.,                                    Ltd.)                                                                          Methyl ethyl ketone/toluene/cyclohexane                                                                   9.0    parts                                        (weight ratio 4:4:2)                                                           ______________________________________                                    

The above-mentioned composition was mixed to form a coating solution. This coating solution was then applied onto a synthetic paper (Yupo FPG #150, made by Oji Yuka Co., Ltd.) by means of a bar coater (No. 1, made by RK. Print Cort Instruments Co., Ltd.) so that the dry weight of the coating solution might be 4.5 g/m², and it was then dried at 100° C. for 15 minutes.

(4) Transfer record

The above-mentioned transfer sheet was superposed upon the material to be recorded so that the ink-applied surface might be brought into contact with the coating solution-applied surface, and a transfer operation was then carried out under conditions of a heat-sensitive head application voltage of 11 V and a printing time of 16.0 milliseconds by heating the heat transfer sheet from its back surface, thereby recording a yellow color having a color density of 1.95.

This color density was measured by the use of a densitometer RD-514 type (filter: latten No. 58) made by U.S. Macbeth Co., Ltd.

The color density was calculated in accordance with the following formula.

    ______________________________________                                         Color density =                                                                             log.sub.10 (I.sub.0 /I)                                           I.sub.0 =    Intensity of reflected light from a                                            standard white reflector plate                                    I =          Intensity of reflected light from a test                                       piece.                                                            ______________________________________                                    

For the obtained record, a light resistance test was made at a black panel temperature of 63°±2° C. for 40 hours by the use of a xenon fade meter (made by Suga Tester Co., Ltd.). As a result, the record scarcely changed, and the stability of the image at a high temperature and a high humidity was also excellent.

The fastness of the recorded image was evaluated by allowing the image to stand in an atmosphere at 50° C. for 48 hours, and then observing the sharpness of the image and a coloring state on a white paper by which the image was rubbed. As a result, the sharpness of the image did not change and the white paper was not colored, which meant that the fastness of the recorded image was good.

EXAMPLE 50

A compound represented by the formula (0) was prepared as follows.

10 parts of a compound having the formula (B) and 0.4 part of pyridine were added to 60 parts of o-dichlorobenzene, and the solution was then heated up to 100° C. Next, 7.2 parts of thionyl chloride were added thereto, and reaction was then carried out at 100° C. for 2 hours. Afterward, excessive thionyl chloride was removed at 100° C. under reduced pressure to obtain 10 parts of a compound of the following formula (N) which was the precursor of the desired product (O). ##STR62##

Next, 7.7 parts of piperazine were added to 40 parts of pyridine, and the solution was then heated up to 80° C. 10 parts of the compound of the formula (N) were then added thereto, and reaction was carried out at 80° C. for 3 hours to obtain 11 parts of the compound represented by the formula (0). The absorption maximum wavelength (λmax) of this compound in toluene was 445 rim. ##STR63##

In accordance with the same procedures as in Example 49, an ink, a transfer sheet and a material to be recorded were prepared, and transfer record was then carried out, to obtain a yellow record having a color density of 1.80.

For this record, a light resistance test was made in the same manner as in Example 49, and as a result, the record scarcely changed and the stability of the image at a high temperature and a high humidity was also excellent.

For the recorded image, a fastness test was made in the same manner as in Example 49, but as a result, the sharpness of the image did not change and a white paper was not colored, which meant that the fastness of the recorded image was good.

EXAMPLE 51

A compound represented by the formula (P) was prepared as follows.

5 parts of a compound having the formula (0) and 0.9 part of potassium carbonate were added to 40 parts of N,N-dimethylformamide, and the solution was then heated up to 70° C. Next, 5.7 parts of n-butyl tosylate were added thereto, and reaction was then carried out at 70° C. for 3 hours to obtain 5.5 parts of a compound of the following formula (P). The absorption maximum wavelength (λmx) of this compound in toluene was 448 nm. ##STR64##

In accordance with the same procedures as in Example 49, an ink, a transfer sheet and a material to be recorded were prepared, and transfer record was then carried out, to obtain a yellow record having a color density of 1.95.

For this record, a light resistance test was made in the same manner as in Example 49, and as a result, the record scarcely changed and the stability of the image at a high temperature and a high humidity was also excellent.

For the recorded image, a fastness test was made in the same manner as in Example 49, but as a result, the sharpness of the image did not change and a white paper was not colored, which meant that the fastness of the recorded image was good.

EXAMPLES 52 TO 68

In accordance with the same procedure as in Example 49, 50 or 51, yellow dyestuffs shown in Table 9, inks, transfer sheets and materials to be recorded were prepared, and transfer record was then performed to obtain records shown in Table 9.

For these records, a light resistance test was made in the same manner as in Example 49, and as a result, the records scarcely changed, and the stability of the images at a high temperature and a high humidity was also excellent.

For the recorded images, a fastness test was made in the same manner as in Example 49, but as a result, the sharpness of the images did not change and a white paper was not colored, which meant that the fastness of the recorded images was good.

The measured results of the maximum transfer concentration, and evaluated results of light resistance and fastness of the recorded image are set forth in Table 9.

                                      TABLE 9                                      __________________________________________________________________________                                                              Fastness              Ex-                                            Maximum                                                                              Light                                                                              of the                am-                                            Optical                                                                              Resis-                                                                             Recorded              ple                                                                               Structural Formula                          Density                                                                              tance                                                                              Image                 __________________________________________________________________________     52                                                                                 ##STR65##                                  1.90  ◯                                                                      ◯         53                                                                                 ##STR66##                                  1.90  ◯                                                                      ◯         54                                                                                 ##STR67##                                  1.92  ◯                                                                      ◯         55                                                                                 ##STR68##                                  1.90  ◯                                                                      ◯         56                                                                                 ##STR69##                                  1.90  ◯                                                                      ◯         57                                                                                 ##STR70##                                  1.75  ◯                                                                      ◯         58                                                                                 ##STR71##                                  1.90  ◯                                                                      ◯         59                                                                                 ##STR72##                                  1.85  ◯                                                                      ◯         60                                                                                 ##STR73##                                  1.80  ◯                                                                      ◯         61                                                                                 ##STR74##                                  1.85  ◯                                                                      ◯         62                                                                                 ##STR75##                                  1.90  ◯                                                                      ◯         63                                                                                 ##STR76##                                  1.88  ◯                                                                      ◯         64                                                                                 ##STR77##                                  1.93  ◯                                                                      ◯         65                                                                                 ##STR78##                                  1.91  ◯                                                                      ◯         66                                                                                 ##STR79##                                  1.89  ◯                                                                      ◯         67                                                                                 ##STR80##                                  1.85  ◯                                                                      ◯         68                                                                                 ##STR81##                                  1.88  ◯                                                                      ◯         __________________________________________________________________________

With regard to the evaluated results of the light resistance and the fastness of the recorded image, the good results were denoted by o and the bad results by x.

COMPARATIVE EXAMPLES 12 TO 14

Inks, transfer sheets and materials to be recorded were prepared in accordance with the same procedure as in Example 49 by the use of yellow dyestuffs shown in Table 10, and transfer record was then carried out. Furthermore, a light resistance test and a fastness test were also performed in the same manner as in Example 49. As a result, products which could simultaneously meet the requirements of the maximum transfer density, the light resistance and the fastness could not be obtained, and images were unclear and white papers were noticeably colored, which meant that these products were poor.

                                      TABLE 10                                     __________________________________________________________________________     (Comparative Examples)                                                                                        Maximum                                                                        Optical                                                                              Light(*)                                                                             Fastness of the                     Example                                                                             Structural Formula        Density                                                                              Resistance                                                                           Recorded Image                      __________________________________________________________________________     12                                                                                   ##STR82##                1.2   ◯                                                                        ◯                       13   C.I. Disperse Yellow-3    1.65  x     x                                   14   C.I. Solvent Yellow-56    1.75  x     x                                   __________________________________________________________________________      (*) With regard to the evaluated results of the light resistance and the       fastness of the recorded image, the good results were denoted by               ◯ and the bad results by x.                                   

What is claimed is:
 1. A transfer sheet which comprises abase sheet and a dyestuff-supporting layer formed all over the base sheet, the dyestuff contained in the dyestuff-supporting layer being the dyestuff for heat-sensitive transfer record represented by the formula (1) ##STR83## wherein R₁ is an alkyl group having 1 to 8 carbon atoms or cycloalkyl group;R₂ is a hydrogen atom, halogen atom, alkoxy group which may be substituted, alkylthio group which may be substituted or arylthio group which may be substituted; R₃ is a branched alkyl group having 3 to 5 carbon atoms, an O-substituted oxycarbonyl group, an N-substituted aminocarbonyl group in which the N-substituted group may form a ring, or a substituted or unsubstituted heterocyclic ring having two or more hetero atoms of one or more kinds selected from the group consisting of a nitrogen atom, oxygen atom and sulfur atom.
 2. A transfer sheet according to claim 1, wherein R₁ is a branched alkyl group having 3 to 5 carbon atoms.
 3. A transfer sheet according to claim 1, wherein R₁ is an isopropyl group.
 4. A transfer sheet according to claim 2, wherein R₂ is a hydrogen atom.
 5. A transfer sheet according to claim 2, wherein R₃ is an alkyloxycarbonyl group.
 6. A transfer sheet according to claim 2, wherein R₃ is a dialkylaminocarbonyl group.
 7. A transfer sheet according to claim 2, wherein R₃ is a substituted oxazoline group.
 8. A transfer sheet according to claim 1, wherein R₁ is an isopropyl group, R₂ is a hydrogen atom, and R₃ is a dialkylaminocarbonyl group.
 9. A transfer sheet which comprises a base sheet and a dyestuff-supporting layer formed all over the base sheet, the dyestuff contained in the dyestuff-supporting layer being the dyestuff for heat-sensitive transfer record represented by the formula (2): ##STR84## wherein R₂ is a hydrogen atom, halogen atom, alkoxy group which may be substituted, alkylthio group which may be substituted or arylthio group which may be substituted; andR₃ is a branched alkyl group having 3 to 5 carbon atoms, or a substituted or unsubstituted heterocyclic ring having two or more hetero atoms of one or more kinds selected from the group consisting of a nitrogen atom, oxygen atom and sulfur atom. 